Overview
- Description
- The Opportunistic Encryption feature of HTTP2 (RFC 8164) allows a connection to be transparently upgraded to TLS while retaining the visual properties of an HTTP connection, including being same-origin with unencrypted connections on port 80. However, if a second encrypted port on the same IP address (e.g. port 8443) did not opt-in to opportunistic encryption; a network attacker could forward a connection from the browser to port 443 to port 8443, causing the browser to treat the content of port 8443 as same-origin with HTTP. This was resolved by disabling the Opportunistic Encryption feature, which had low usage. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.
- Source
- security@mozilla.org
- NVD status
- Analyzed
Risk scores
CVSS 3.1
- Type
- Primary
- Base score
- 6.5
- Impact score
- 3.6
- Exploitability score
- 2.8
- Vector string
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
- Severity
- MEDIUM
CVSS 2.0
- Type
- Primary
- Base score
- 4.3
- Impact score
- 2.9
- Exploitability score
- 8.6
- Vector string
- AV:N/AC:M/Au:N/C:N/I:P/A:N
Weaknesses
- nvd@nist.gov
- CWE-346
Social media
- Hype score
- Not currently trending
Configurations
[
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "A22FDA8A-B862-4383-9C8E-C162713AB01B",
"versionEndExcluding": "94.0"
},
{
"criteria": "cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "DEA65EE6-233C-4CC1-83E8-316748943DAF",
"versionEndExcluding": "91.3.0"
},
{
"criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "65E19CA9-5FDF-4253-8D56-FD82239F7D93",
"versionEndExcluding": "91.3.0"
}
],
"operator": "OR"
}
]
},
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252"
},
{
"criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73"
},
{
"criteria": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "FA6FEEC2-9F11-4643-8827-749718254FED"
}
],
"operator": "OR"
}
]
}
]